A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. comprising part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
Lithographic apparatus are known to use multiple alignment arrangements. Reference is, e.g., made to K. Ota et al., New Alignment Sensors for Wafer Stepper, SPIE, Vol. 1463, Optical/Laser Microlithography IV (1991), p. 304-314, and N. R. Farrar et al., Performance of through-the-lens/off-axis laser alignment systems and alignment algorithms on Nikon wafer steppers, SPIE Vol. 1673, Integrated Circuit Metrology, Inspection, and Process Control VI (1992), p. 369-380. All of the alignment arrangements use their own, distinct marks on, e.g., a substrate to be exposed and/or a substrate table supporting the substrate.